Core-baking apparatus.



No. 7|2,533'. Patented Nov. 4, I902.

A. M. HEWLETT.

CORE BAKING APPARATUS.

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CORE BAKING APPARATUS.

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A. M. HEWLETT. com-i BAKING APPARATUS. (Applicatiofl filed Feb. 17 1902.

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A. M. HEWLETT. CORE BAKING APPARATUS.

\Application filed Feb. 17, 1902.)

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A. M'. HEWLE'I T.

CORE BAKING APPARATUS.

(Application filed, Feb. 17, 1902.) (No Model.)

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UNITED I STATES PATENT OFFICE.

. A LFREDM. HEWLETT, OF KEIVANEE, ILLINOIS.

CORE-BAKINGAPPARATUS.

SPECIFICATION forming part of -Letters Patent No. 712,533, datedNovember 4, 1902. Application filed February 17, 1902. Serial No.94,440. N model-l To all whom it 772/001] concern:

Be it known that I, ALFRED M. HE LETT, a citizen'ofthe United States,residing at Kewanee, in the county of Henry and State of Illinois, haveinvented certain new and useful Improvements in Core-Baking Apparatus,of which the following is a specification, reference being had to theaccompanying drawings.

Sand cores as usually employed in foundries are composed of sand mixedwith some kind of a binder that will make the core very strong after ithas beenbaked andcooled, and this binder must be of such a nature as tosoften when the iron or brass comes in con The iron or brass when in amolten state must lie smoothly against the core, and if the hinder orcore compound is not softened by the heated metal, but remains hard, themetal will blow or not lie up to it; yet the core must be very strong inorder to stand the strain when the.

molten metal first strikes the core. Oi1,(principally linseed-0H,)rosin, molasses, and glucose are the principal bases for all hinders orcore compoundspand in order to bake cores made by these compounds it isnecessary to have a heat sufficient to practically fuse the rosin,glucose, or other core compound, and when oil is usedthe heat must besufficient to actually bake itdry.

My present invention has to do with apparatus for baking cores, and,generally speaking, has for its object to provide an improved bakingapparatus which operates continuously to conductthe cores into, through,and out of a baking-oven and to cool them before they are handled, sothat they are not readily susceptible to injury.

In baking cores by a continuously-operating apparatus acting to conductthe cores continuously into and through a'baking-oven it is necessary tobake the cores quickly in order to avoid great length in the furnace,

and it is therefore necessary to secure a very high temperature in thefurnace-as, forexample, from 400 to 700 Fahrenheitand even with thishigh temperature it is necessary to have the furnace from sixty toseventy feet long in order to bake cores of even moderate size in anygreat quantity. It is there fore impracticable to use indirect orradiated heat, such as that furnished by steam-coils, to heat the oven.In using steam it is economically impossible to maintain a temperaturemuch, if any, higher than 250 Fahrenheit in the baking-chamber and havethe two ends of the furnace constantly open to'a sufficient extent toallow the passage of the endless carrier, with the cores carriedthereby, and with a temperature of even 250 it is impossible toeconomically and successfully bake cores in which binders composed ofrosin,.glucose, molasses, oil, or similar substances are employed. Itsuperheated steam should be employed, a temperature sufiiciently highmight be obtained; butit would beeconomicallyinoperative,sincetheexpense of so maintaining thetemperature would be enormous in addition to the expense of keeping upthe pipes and coils through which the superheated steam would pass. Itis therefore necessary from an economical and practical standpoint toprovide direct means for heating the baking-oven, and this, broadlyconsidered, is one of theprincipal features of my present invention.

In an oven arranged to operate in connection with a continuously-movingcarrier by which the cores are carried into and through the oven it isnecessary that the ends of the even be open constantly and that theopening be sufficiently large to permit of the free passage of thecarrier, with its lead, of course. It is also necessary in order tosatisfactorily bake the cores that the temperature of the baking chamberbe substantially uniform throughout, and to secure such uniformtemperature notwithstanding the constantlyopen end of the furnace is animportant object of my invention, and the apparatus by which this isaccomplished constitutes another feature of myinvention. Furthermore, itis also highly important in the baking of cores that the temperature benot only uniform throughout all .parts of the oven, but also that meanshe provided for insuring the subjection of the cores to the propertemperature for the proper length of time. In order to insure the properbaking of the cores regardless of the rising or falling of thetemperature of the oven, it isnecessary that means be provided forincreasing the length of time thatthe cores remain in the oven whenthetemperature of the oven falls and for decreasing the time duringwhichthe cores remain in the oven when the temperature of the oven1l.-GS. To provide mechanism by-which this is automatically accomplishedis another object of my invention, and I accomplish it, as hereinafterset forth, by automatically varying the speed of the carrierincreasingit when the temperature of the oven rises and decreasing it when thetemperature of the oven falls. It is further desirable to automaticallyoperate the drafts so that a substan tially constant temperature ismaintained in the oven, and apparatus for this purpose also forms afeature of my invention.

In addition to the actual baking appliances my invention includesapparatus by which the work of preparing cores for the foundry isconducted with a minimum of loss from damage to the cores. Heretoforethe baking of cores has been usually accomplished by the use of ovens ofeither one of two types. In one form of oven the green cores have beencarried into the oven on trucks or boards and have been transferred byhand to shelves 0r racks in the oven and allowed to remain there untilproperly baked. With this form ofapparatus itis necessary to remove thebaked cores from the oven while still hot, with a resulting largepercentage of loss from damage to the cores, since the hot cores aresoft and readily susceptible to damage in handling' In the second formof apparatus heretofore em ployed the cores have been placed on swingingshelves movable into and out of the oven, so that the cores could beintroduced into the oven or withdrawn therefrom without the workmengoing into the oven; but this apparatus also is objectionable for thereasons above given, since the handling of the cores, both in. theirgreen state and when hot, is necessary. I

My invention provides means by which the necessity of handling the coreswhen in a condition in which they may readily be damaged is avoided,except as regards placing the green cores on the carrier. I employ acontinuously-moving carrier which receives the green cores at one endand conducts them into, through, and out of the oven continuously andalso for a sufficient distance heyond the oven to enable them to coolproperly before they are removed. In this Way I avoid all liability ofdamage from handling after the cores have been baked, since when coolthe cores are hard and may be handled with impunity. I further provide acontinuously-moving carrier by which the cores are conducted fromthetables at which they are formed to the baking-oven carrier, and areconsequently delivered thereto in better condition and. with less lossfrom damage than would-be the case it they were carried by workmen fromthe forming-table to the baking-oven carrier.

A further object of my invention is to provide for properly baking coresof different sizes and shapes simultaneously in the same oven. As iswell understood, the cores of diforent sizes and shapes frequentlyrequire to be baked for difierent lengths of time at a giventemperature, and in order to bake such cores simultaneously I provide aplurality of endless carriers moving through the same furnace atdifferent rates of speed, so that by properly distributing the coresupon the carriers a variety of sizes and shapes may be properly baked inthe same oven at the same time.

In addition to the points above mentioned my invention also comprisescertain details of construction, which will be'hereinafter set forth. p

The process which the apparatus herein described is designed to effectforms the subject-matter of an application for patent of even dateherewith. I

In the accompanying drawings, Figure 1 is a side elevation of an oven,showing parts of the carrier and supporting devices therefor. Fig. 2 isa cross-section on line 2 2 of Fig. 7. Fig. 3 is a plan view of thereceiving end of the apparatus, illustrating the carriers of thebaking-oven and the apparatus by which the green cores are conductedthereto. Fig. tis a sectional detail of part of the controllingapparatus for regulating the speed of the carriers of the baking-oven.Fig. 5 is a side elevation of the carrying devices, the oven be-' 111gin section, showing the receiving end of the apparatus. Fig. 6 is asimilar view showing the outlet end of the oven, the carrier, and thereceiving-racks for the cores. Fig. '7 is a horizontal section of theoven, showing the grates. Fig. 8 is 'a plan view of the outlet end ofthe oven and illustrating also the carriers. Fig. 9 is a side elevationof the discharge end of the carriers, showing the driving mechanismtherefor; and Fig. 10 is a plan view of the same, showing also the racksto which the finished cores are transferred and the position of themolding-machines with reference thereto.

11 indicates the oven, the construction of which is best shown in Figs.1, 5, 6, and '7. As shown in Figs. 2, 5, and 6, the oven 11 isconsiderably longer than it is wide and is open at both ends near thetop, the openings extending from side to side. The upper edge of thefront wall 12 of'the oven forms the lower boundary of the opening at theinlet end of the oven, while the upper edge of the rear wall 13 formsthe'lower boundary of the outlet-opening. The oven 11 is provided with aplurality of fire boxes or grates 14, the number depending on the lengthof the oven. As shown in Fig. 7, the grates 14 are distributed equallyatopposite sides of the oven and are placed at different distances fromthe ends thereof, the'idea being to'distribute the grates as nearly aspossible throughout the area of the oven. Each of the grates 14 isinclosed by a wall 15, which forms three sides of a square and is openat the top, so that the site ends of the oven the heat from the gratesheat may rise into the'upper portion of the oven, where the cores arecarried. Each grate is provided with upper and lower doors 16 17, 1respectively, forsupplying fuel and for re-. moving the ashes. The doors17 also serve. as dampers to regulate the draft and to that end arehinged at their upper edges, as shown at 18 in Fig. 1. Provision is madefor the. automatic adjustment of the dampers 17, as will be hereinafterdescribed.

19 20 indicate smoke-stacks placed at oppo-f site ends and atoppositesides of the oven, as best shown in Figs. 1 and 7. V

21 22 indicate fines extending across the oven at the ends thereof, saidfines commu nicating with the stacks 19 20, respectively, andopeninginto the oven. By providing the stacks at the opposite sides andat the oppois conducted toward the ends of the oven, so that the endseven adjacent to the openings are substantially as hot as theintermediate portions of the oven. Furthermore, the location of thegrates at opposite sides and at intervals throughout the ovenefliectually distributes the heat and maintains a substantially uniformtemperature throughout the entire oven. The temperature may be variedbyopening or closing the drafts.

A B C indicate endless carriers, which, as shown in Fig. 2, are arrangedside by side and are adapted to move through the oven, returning overthe roof thereof, as bestshown in Figs. 5 andi6. As shown, each of thecarriers is composed of two endless chains consisting of links 23,connected together at their ends, i the two chains of each carrier beingconnected by transverse rods 24, which also serve as a means ofconnecting the links of each .chain together. The ends of the rods 24project beyond thelinks in which they are carried and carry rollers25,which are adapted to run on rails 26, provided for the purpose. Thelength of the rods 24 is such that the two chains composing each carrierare held at a comparatively short distance apart, forming narrowtraveling conveyers, and the links 23 of eachcliain are of slightlygreater width than the diameterof the rollers 25,-sothat the conveyersare adapted to receive metal plates ortrays, on which the cores areplaced to be conducted through the oven.

As shown in Fig. 2, there are three pairs of rails extending through theoven, said rails also extending beyond the ends of the oven as faras theendless carriers go, as shown in Figs. 5 and 9., The rails 26 in theoven are mounted on suitable transverse supportingbars 27, as shown inFig, 2, and outside the even they are supported by similar transversebars28, secured in supporting-frames 29, provided at suitable intervals,as. shown in Figs. 5 and 9. The rails 26 are fixedlysecured at one endto their supports, but that. portion of the railswhich extends throughthe oven to the receiving end of the apparatus rests loosely on thetransverse bars 27 and 2S,

so that the rails are free to move longitudinally when expanding or.contracting by reason of variationsin, the. temperature of the oven.

Suitable means may be provided forpreventing them from being displacedlaterally. In Fig. 6 I have shown the rails as beingfixedly secured to asupportBO, provided at the out- .let end of the oven, said support beingprovided with a brace 31 to resist the end thrust occasioned by theexpansion and contraction of the rails.

32 33 34 indicate sprocket-wheels mounted at different distances fromthe inlet end of .the oven in the supportingframes 29, as shown in Fig.5. The sprocket-wheels 3233 .34 are in line, respectively, withthe-carriers opposite ends of the carriers AB 0, respec-.

tively, as shown in Fig. 10. The-latter sprocket-wheels are, however,notadjustable longitudinally.

42 indicates an engine or othersuitable source of power, which in theconstruction illustrated operates through a belt 43 and pulley 44 todrive a shaft 45. Said shaft carries a pinion 46, which meshes with agear 47, mounted on a shaft 48, the latterashaft carrying apinion 49,which meshes with a gear 50, 1 Said shaft 51 carries carried by a shaft51. a pulley 52, which is connected byia belt 53 with a pulley 54,mounted onthe shaft .55 of the sprocket-wheel 39. Said shaft alsocarries a sprocket-wheel 60, which is connected by a link belt 61 with asprocket-wheel 62,

mounted on the shaft 63 of sprocket-wheel 41, which drives carrier G.Theshaft 63 also carries a sprocket-wheel 64, which is connected by alink. belt 65 with a sprocket-wheel 66, mounted onthe shaft 67 ofsprocketwheel 40, which drives carrierB. By thiscon- .struction thethree carriers A B C are driven from the engine 42, but at diiferentrates of speed, since by making the sprocket-wheel 6,0 of less diameter,the sprocket-wheel66 be-' ing next larger and thesprocket-wheel 62 thelargest, the carrier A noves at the highest rate ofspeed, the carrier Bat a slower rate, and the carrier 0 at the slowest rate. object of thisconstruction is to provide for subjecting diiferent kinds and. sizes. of1 cores to the drying temperature for ditferent periods of time, ascertain classes of cores require drying for algreater length of timethan others. 1

While the driving apparatus described The tion access is readily had toeach of the conveyers. Furthermore, the shortest conveyer travels theshortest distance outside the oven, thereby compensating for its reducedspeed. Thisis quite an advantage, especially in loading the carrier 0,since the articles are placed upon it nearest the inlet-opening, andconse{ quently are carried into the oven much sooner than they would beotherwise. Of course the articles carried by the conveyer 0 remain inthe oven a considerably longer time than those carried by either of theother conveyers.

' The driving apparatus is arranged so that the lower portions of theconveyers move through the oven, entering at the inlet end shown in Fig.5 and passing out at the end shown in Fig. 6. The upper portions of thedifferent conveyers are supported upon rails 68, which extend over theoven 11 and from end to end of the apparatus, being supported upontransverse bars 69, placed at suitable points, as best shown in Figs. 1,5, 6, and 9.

As shown in Figs. 6 and 9, the conveyers extend a considerable distancebeyond the outlet end of the oven. arrangement is to provide for coolingthe cores after they have been baked before they are removed from theconveyers. After the cores have been baked and while they are still hotthey are quite tender, andif removed from the carrier or otherwisehandled before:

they have been cooled sufficiently to set there is great danger ofbreakage. the carriers, however, a considerable distance beyond the oventhe cores are carried slowly In the arrangement shown core-racks 71 areprovided between the con veyers and'the foundry, as shown in Figs. 9 and10. are adapted to receive the cores when taken from the carriers. Thecores are then taken from the other side of the racks and carried byhand to the molding-machines or to the part of the foundry where theyare to be used.

The object of this By extending and consequently are not overbaked.

Said racks I The speed of the conveyers is regulated by the heat of theoven, and to this end'the expansion and contraction of the rails 26 isutilized to control the speed of the engine 42. I prefer to use only oneof the rails for this purpose. As already described, the rails 26 aresecured to the support 30 near the outlet end of the oven 11, as shownin Fig. 6. Consequently the expansion or contraction of the rails due tothe heat of the oven causes the ends of the rails at the receiving endof the apparatus to move longitudinally to a greater or less extent,depending on the variations in temperature. To utilize this movement, alever 72 is provided, pivoted at its lower end to a suitable support 73,arranged near the inlet end of the oven, as shown in Fig. 5. To theupper end of the lever 72 is connected a connecting-rod 74, (best shownin Figs. 5, 8, and 10,) which is connected by a lever 76 with abell-crank lever 77, which is in turn connected by a link 77 with acrank 78, which operates a controller or governor 78, carried on theengine 42. In Fig. 4 I have shown a controller consisting of a rotaryvalve 78", the crank 78 being secured upon the stem thereof, so that byswinging said crank the valve may be partially rotated. The controller78, as well as the intermediate mechanism for operating it from the rod74, may, however, be of any approved construction suitable for varyingthe speed of the engine by longitudinal movement of said rod 74, thearrangement being such that when the rod 74 moves in one direction thespeed of the engine is increased and when it moves in the oppositedirection the speed is reduced. In Fig. 4 I have shown one form ofconstruction for this purpose. As therein illustrated, the valve 78 isprovided with passages 78, adapted to register with passages 78 whichcommunicate with the steam-supply passage 78*, the arrangement beingsuch that by rotating the valve 78 the area of the steam-inlet may beincreasedor diminished and the speed of the engine varied accordingly.By this construction it will be seen that if the temperature of thefurnace falls the speed of the conveyers is reduced and the cores arethereby subjected for a longer period of time to the lower temperature,as is necessary to properly bake them. Similarly, if the temperature ofthe oven rises the speed of the conveyers is increased, so that they arenot subjected to the higher heat for so long a time, In a similar mannerthe temperature of the oven automatically controls the drafts, since therod 74 is connected by chains 79 or other suit able flexible connectionsto the ash-pit doors or dampers 17, said chains running over pulleys 80,as shown in Fig. 1.

As shown in Fig. 1, when the rails 26 expand the upper end of the lever72 moves in the direction indicated by the arrow in said figure.Consequently the rod 74 is moved in the same direction, thereby slackingthe operating mechanism, While considerable chains 79 and lowering thedamper 17. When the rail 26 cools and consequently contracts, the rod 74moves in the opposite direction, consequently opening the dampers 17. Asimilar lever, connecting-rod, and chains are provided at both sides ofthe oven, but only one of said connecting-rods extends to the engine.

The green cores are carried to the baking apparatus by means of aconveyer 81, which receives the cores from the tables 82, at which theyare formed, and conducts them to the carriers, as shown in Fig. 3. Saidconveyer 81 is represented diagrammatically in Fig. 3 for the purpose ofillustrating the fact that it is arranged to conduct the green coresfrom the place where they are formed to the carriers of the bakingapparatus, and it should be understood that the shape and the diree-.tion of travel of said conveyer 81 may be varied to suit localconditions. By thus conveying the green cores to the baking apparatusthey are handled only once-to wit, when they'are transferred from theconveyer 81 to the carriers of the baking apparatus-and thus are muchless liable to injury than has heretofore been the case.

Instead of having the conveyers return over the oven, as shown in thedrawings, any other equivalent construction may be em ployed.

From the foregoing description it will be seen that the oven ismaintained at substantially a uniform temperature throughout and thatsuch temperature is maintained at substantially a constant point byautomatically variations in temperature are not apt to occur,

even slight changes atonce vary the speed of the carriers, so that thebaking effect is practically invariable, the cores moving through theoven faster when it ishot and slower when Furthermore, by subjecting theit is cooler. cores to direct heat, as is the case in the apparatusdescribed, they are baked more set forth, and I would say, further, thatI have found by practicalexperience that a very important saving isattained by my im-' proved process, owing to the great reduction in theloss through damage to the cores as: compared with the results securedby meth-' ods heretofore employed.

For heating the oven I preferably employ coke or oil; but wood and coalmay also be used, anthracite coal especially being quite a satisfactoryfuel. The temperature employed should be somewhere between 400 and 700Fahrenheit in order to produce the best results.

I have described in detail the apparatus illustrated in the drawings;but'I Wish it to be understood that my invention is not restricted tothe details of construction of such apparatus, except in so far as suchdetails are particularly claimed.

, That which I claim as my invention, and desire to secure by LettersPatent, is

1. In a core-baking apparatus, the combination of an elongated oven openat its ends, a carrier arranged to move through said oven from end toend,a plurality of direct-heat ing devices for heating said oven, meansfor. moving said carrier continuously through said oven, and meansoperated by the rise and fall of the temperature of the oven forregulating the speed of said carrier, substantially as described. V

3. In a core-baking apparatus, the combination of an oven, an endlesscarrier adapted to move through said oven, means for heating said oven,means for moving said carrier continuously through said oven, and meansoperated by variation in the temperature of the oven for varying thespeed of said carrier, substantially as described.

4. In a core-baking apparatus, the combination of an oven, an endlesscarrier adapted to move through said oven, means for heating said oven,means for moving said carrier continuously through said oven, and meansoperated by an increase in the temperature of the oven for increasingthe speed of the carrier and by the decrease in the temperature of theoven for decreasing the speed of the carrier, substantially asdescribed.

5. In a core-baking apparatus, the combination of an oven, means forheating said oven, an endless carrier adapted to move through said oven,rails supporting said carrier, means for moving said carriercontinuously through said oven, and means operated by expansion andcontraction of one of said rails for varying the speed of the carrier,substantially as described.

6. A core-baking oven in combination with a carrier adapted to movethrough said oven, and means automatically operated by variation in thetemperatureof the oven for varying the speed of said carrier,substantially as described.

7. A core-baking oven in combination with a continuously-moving carrieradapted to move through said oven, and means automatically operated byvariation in the temperature of the oven for varying the speed of saidcarrier, substantially as described.

8. A core-baking oven having inlet and outlet openings at its ends,conveyer mechanism adapted to traverse said oven, passing through saidopenings, fire-boxes and chimneys communicating with the opposite endportions of said oven whereby heat is supplied and distributed uniformlythroughout the oven, substantially as described.

9. A core-baking oven having inlet and outlet openings, fire-boxes atopposite sides of said oven and communicating therewith, and stacks atopposite sides of said oven near the opposite ends thereof, said stackscommunicating with said oven, substantially as described.

10. In a core-baking apparatus, the combination of an elongated oven,acarrier arranged to move through said oven from end to end, means formoving said carrier continuously throughsaid oven, a plurality offire-boxes for distributing heat uniformly throughout the oven, damperscontrolling combustion in said fire-boxes,and means extendingsubstantially from end to end of said oven and operated by variation inthe temperature at any point in the length thereof for adjusting saiddampers and thereby regulating the temperature of the oven,substantially as described.

11. In a core-baking apparatus for baking cores of difierent sizes, thecombination of an oven having inlet and outlet openings, a plurality ofendless carriers each traversing said oven and passing through saidopenings, and means for moving said carriers at different rates ofspeed, whereby cores of smaller sizes may be moved through the ovenfaster than those of .larger sizes, substantially as described.

12. In acore-baking apparatus, the combination of an oven havinginletand outlet openings, a plurality of endless carriers movable throughsaid oven, means for moving said carriers at difierent rates of speed,and means operated by variation of the temperature in the oven forvarying the speed of said carriers, substantially as described.

13. In a core-baking apparatus, the combination of a baking-oven, meansfor heating said oven to a core-baking temperature, an endless carrieradapted to move through said oven to carry the cores into and out ofsaid oven, said carrier extending a sufficient distance outside of saidoven, to permit the cores to cool and harden on said carrier afterbaking, and means for operating said carrier, substantially asdescribed.

14:. In a core-baking apparatus, the combination of an oven havinginletand outlet openings, means for heating the oven to a corebakingtemperature, a plurality of endless carriers extending through and asufficient distance beyond the outlet-opening of the oven to permit thecores to cool and harden on the carriers after baking, and means foroperating said carriers at different rates of speed, substantially asdescribed.

nation of an oven havinginlet and outlet openings, a plurality ofendless carriers arranged in parallelism and movable into, through andout of said oven, and means for moving said carriers, said carriersbeing arranged to extend for different distances outside of the oven,substantially as described.

17. In a core-baking apparatus, the combination of an oven, acore-carrier, and means operated by variation of the temperature in theoven for regulating the speed of said carrier, substantially asdescribed.

18. In a core-baking apparatus, the combination of an oven, a pluralityof carriers, means for moving said carriers at diiferent rates of speed,and means operated by variation of the temperature in the oven forregulating the speed of said carriers, substantially as described. I

19. A core-baking oven having direct-heat heating devices, apparatus forregulating the operation of said heating devices, and controlling meanslocated in said oven and exposed to direct heat from said heatingdevices for actuating said regulating apparatus, substantially asdescribed.

20. A core-baking oven having direct-heat heating devices, apparatus forregulating the operation of said heating devices, and controlling meansin said oven and extending substantially from end to end thereof foractuating said regulating apparatus, substantially as described.

21'. In a core-baking apparatus, the combination of an oven open at itsends, a plurality of carriers movable side by side into, through and outof said oven, means for moving said carriers at different rates ofspeed, and means operated by variation in the temperature of the ovenfor varying the speed of said carriers, substantially as described.

22. In a core-baking apparatus, the combination of an oven havinginletand outlet openings, a plurality of endless carriers arranged inparallelism and movable into, through and out of said oven, an endportion of one of said carriers extending beyond the corresponding endportion of an adjacent carrier, and means for moving said carriers,substantially as described.

ALFRED M. HEWLETT.

Witnesses:

A. G. ONEILL, CHAS. F. CULLoM.

